The present invention relates generally to orthopedic devices and more particularly to improved ankle braces and supports and the method of their manufacture.
The present day market for orthopedic devices offers a number of different ankle products of varying types. The product types vary in many respects and particularly in the amount or degree of stabilization provided. Ankle products range from simple compressive elastic sleeves to rigid, plastic immobilizing braces. The most common ankle product is a lace-up style brace that is indicated for both rehabilitative and preventative use. These braces help medially and laterally stabilize the ankle joint to prevent inversion and eversion (twisting) of the ankle, while still allowing for functional dorsi and plantar flexion. This type of stabilization is typically achieved in traditional ankle braces with metal, plastic or spring type stays, boning or inserts. By stabilizing the medial and lateral sides of the ankle joint, the brace is indicated to prevent further injury and treat strains and 1st, 2nd, and 3rd degree ankle sprains. The brace is also employed as a preventative prophylactic to help avoid ankle sprains during activity. Historically, ankle braces with rigid stays or inserts have been utilized for these indications.
However, metal or plastic stays or inserts can dig into the tender tendons that these braces were designed to protect. Additionally, rigid stays and inserts cannot conform to the unique ankle shape to give the intimate support and stabilization necessary.
A sample of prior art patents illustrating some of these devices includes the following:
U.S. Pat. No. 4,724,847, issued Feb. 16, 1988, to Ronald E. Nelson, shows a soft orthopedic ankle support that has a plurality of pockets. Rigid stay members are inserted into the pockets to form a rigid structure that surrounds and immobilizes the ankle. U.S. Pat. No. 4,280,488 shows a similar stay stiffened soft orthopedic ankle support.
U.S. Pat. No. 5,853,380, issued to John J. Miller, Dec. 29, 1998, shows an ankle and foot orthopedic device wherein inner and outer layers of soft plastic materials are assembled in a sandwich around a rigid copolymer plastic stay which cradles the ankle and foot. In fabricating the device the inner layer of plastic material is heated and then wrapped around a plaster mold. The mold is equipped with suction by which the sheet can be sucked down to conform to the shape of the mold. The outer surface of the inner layer is then abraded and the stay is placed over the abraded surface. Once the stay is in place, adhesive is sprayed over the entire exposed surface of the inner layer and the stay. Finally the outer layer of plastic is heated and wrapped around the inner layer and stay, sucked down by the vacuum to conform to the shape of the mold, cooled, and trimmed to shape.
U.S. Pat. No. 5,899,872, issued May 4, 1999 to Robert F. Gilmore, describes a foot and ankle support which includes a soft appliance, somewhat elastic, boot element. The somewhat elastic boot element is tightened by means of spaced flaps secured by hook and loop fasteners. Conventional straps encircle the boot. In another embodiment a rigid brace is applied over the boot and affixed by one or more of the straps.
U.S. Pat. No. 5,069,202, issued Dec. 3, 1991, to Steven D. Prock, shows a stirrup type of ankle brace which includes a foot shell having rigid vertical and horizontal portions hingedly connected. This shell is held onto the ankle and foot of the wearer by straps.
U.S. Pat. No. 3,073,305, issued Jan. 15, 1963, to Ernest R. Biggs, et al., shows an ankle brace including a fabric sleeve fitting along the foot and ankle with a strap arrangement spiraling up the leg, and essentially vertical stays inserted in pockets along the leg part of the sleeve.
U.S. Pat. No. 5,472,414, issued Dec. 5, 1995, to Michael K. Detty, describes a one-size-fits-all ankle brace comprising a base of plush fabric covered neoprene having an upper ankle surrounding portion and an upper pair of mounting straps, and a lower foot surrounding portion with a lower pair of mounting straps. The base member is folded into an ankle and foot encasing position with the upper straps wrapped around the ankle and the leg just above the ankle, and the lower straps wrapped around the ankle arch and instep. Hook and loop fasteners hold the straps in position.
U.S. Pat. No. 6,024,712, issued Feb. 15, 2000, to Joseph M. Inglesias, describes an ankle brace using an inner fabric support which extends around the ankle. An outer plastic exo-support is injection molded into the fabric support to resist motion of the injured ankle in undesired directions. The exo-support has side members extending upwardly from a base to provide stirrup like support.
While the aforementioned prior art ankle braces may be generally suitable for their intended purposes, they nevertheless leave something to be desired from the standpoints of accommodating various sized ankles while supplying sufficient customized support, and ease and economy of manufacture. Thus, a need exists for an ankle brace which fits a range of sizes, which is simple in construction and manufacture, easy to use, and which has means to adjust and customize the support applied by the brace without producing the aforementioned adverse effects of metal or other rigid stays.
It is a primary object of the invention to eliminate the above described problems and shortcomings of the prior art.
It is another object of the invention to provide an improved ankle support comprising a unique combination of low temperature formable plastic foam and a sewn orthopedic soft appliance, which provides ease of economic manufacture.
It is yet another object of the invention to provide an improved methodology for manufacturing an improved ankle support which is fabricated from a combination of low temperature formable plastic foam and a sewn orthopedic soft appliance.
It is a further object of the invention to provide a combination of a sewn soft ankle brace with a contoured semi-rigid support shell of molded foam to produce a snug fitting orthopedic device which gives improved stabilization of the ankle joint.
It is yet a further object of the invention to provide such a combination orthopedic device in which the shell is molded with a unique shape or configuration that flexes around the ankle to provide medial and lateral stabilization without digging into the skin.
It is another object of the invention to provide such an orthopedic wherein a uniquely J-shaped portion of the shell is supported from a collar on the shell and sewn to an inner sock or sleeve to cradle and support the ankle joint without creating pressure points on the sensitive ankle malleoli.
It is yet another object of the invention to provide an orthopedic of the foregoing type wherein the shell has a leg encircling collar which carries depending stiffeners and has a width sufficient to provide cantilever type tensioning of one or more of such stiffeners against an extremity of a wearer.
It is yet another object of the invention to provide an orthopedic of the foregoing type wherein the shell is of an asymmetric shape to even further avoid the creation of pressure points on the ankle malleoli.
The present invention is directed to a unique incorporation of the technology of low temperature, formable plastic foam with sewn fabrics in the manufacture of improved orthopedic appliances. Particularly the invention is directed to integration of these two approaches for use in ankle and knee braces.
In sewn orthopedic soft appliances and braces the most common means to obtain the rigidity necessary to stabilize the injured joint is by using metal or plastic strips called xe2x80x9cstaysxe2x80x9d. These stays are actually sewn to the product to prevent movement of the joint. However, in some product applications stays simply cannot conform to the anatomy of the patient to provide the necessary support and immobilization. Additionally, in some cases, stays may be too rigid, too uncomfortable or xe2x80x9cdigxe2x80x9d into the skin.
Low temperature, formable plastic, closed-cell polyolefin foams, such as the foam sold under the trademark VOLARA, have been used as splinting materials in a number of orthopedic products. VOLARA foam is formable by a variety of techniques and is readily available.
According to the present invention low temperature, formable plastic, closed-cell foams are sewn to a soft orthopedic appliance to obtain the necessary rigidity and conformability without stays. This provides a more comfortable, better fitting product for greater conformability and immobilization. The product is to be contrasted with products which incorporate a soft appliance in an outer shell in such a manner as to detract from or eliminate the advantages provided by a soft appliance. One example of such a prior arrangement uses injection molding to incorporate a soft appliance into a hard outer shell which encompasses a substantial area of the skin of the wearer. The inventive combination of the technologies of formable foams with traditional sewn orthopedic products yields unique products having improved product function.
In one particular embodiment of the invention, low temperature, formable plastic, closed-cell foam is used in combination with a traditional sewn product to obtain better stabilization of the ankle. A semi-rigid formed foam xe2x80x9cshellxe2x80x9d of a unique shape provides the necessary medial and lateral stabilization. This is to be contrasted with products which include a relatively rigid boot encasing the bottom of the foot.
In producing the new brace, a polyolefin foam, such as VOLARA, is laminated with nylon or the like fabric on both of its surfaces. The thus laminated foam is then cut to desired blank shape by standard material clickers. This blank of flat foam laminate is then sewn to the soft, nylon or nylon like fabric of the soft brace, also in flat blank shape. The combined foam sheet and attached soft brace blanks are then subjected to heat and pressure forming after the sewing is complete. The molding step transforms the previously soft foam into a semi-rigid skeletal xe2x80x9cshellxe2x80x9d that extends around but does not substantially completely encase the ankle. The soft appliance provides the basic support, while the skeletal shell provides tailored localized flexible stiffening. This approach and its associated production methodology is to be contrasted with more elaborate and costly known techniques.
The combination of the soft ankle brace with a contoured semi-rigid support shell gives a contoured, snug fit for much better stabilization of the ankle joint. The shell is molded with a unique skeletal shape or configuration that flexes around the ankle to provide medial and lateral stabilization without digging into the skin. The foundation for the support provided by the skeletal elements of the shell is an adjustable circumferential collar secured around the leg above the ankle joint. From this collar depend a pair of generally diametrically opposite medial and lateral fingers or stiffeners which terminate in one or two unique J-shaped ends. The collar and fingers are sewn to the soft brace to provide a unique cradling and support to the ankle joint without creating pressure points on the sensitive ankle malleoli. Aside from the foundational collar the shell does not provide extensive area coverage. It does provide tailored stiffening in selected locations, thereby enhancing the basic support provided by the soft appliance. The collar has a width sufficient to provide cantilever type tensioning of one or more of the fingers or stiffeners against the extremity of the wearer.
With this product the fragile or damaged ankle tendons and the sensitive ankle malicoli are protected from further impact or shock. Using low temperature, formable plastic, closed-cell foam, such as VOLARA, as the support shell in the new configuration replaces the need for a metal stay or plastic inserts. The molded foam is sufficient to stabilize the ankle joint but is much less rigid than previously used steel or aluminum or rigid plastics. This gives a more conforming fit, provides a layer of molded foam protection, and eliminates the use of rigid metal around the sensitive tendons and malleoli.
In one preferred embodiment of the improved ankle brace there is provided a soft fabric sock-like sleeve having a cutaway open heel and toe. This provides basic soft sewn appliance support to the joint to be protected. A flat sheet of a compressible heat formable closed cell polyolefin, such as VOLARA, is sandwiched between surface sheets of woven fabric, such as nylon or the like. This soft laminated composite material is then cut to a predetermined pattern to form a blank having a flat skeletal configuration. The configuration is designed so that when it is shaped into a generally cylindrical form it will provide an above the ankle leg encircling collar at its top. The width of the collar is such as to form a foundation for supporting the skeletal elements of the shell, including elongated depending stiffeners. It is a feature of the invention that the collar provides cantilever type support for depending stiffeners that are relatively narrow in width. However, the stiffeners are provided with the desired semi-rigidity by increasing their effective cross section. Thus the desired flexural strength may be provided by an increase of the thickness or by the use of stiffening ridges or the like. In certain embodiments the stiffeners may be further adjustably supported by straps. This permits individual customization of degree of support afforded by the stiffeners.
The open heel and toe, sock-like soft brace material, also in its flat blank configuration, is then sewn to the skeletal shell blank in a predetermined stitching pattern. The collar of the shell blank is sewn to the upper or above the ankle portion of the soft brace fabric so as to substantially encircle it when the soft brace is in its sock or sleeve form. Depending from this collar are substantially vertical fingers which terminate in one or two J shaped arms disposed to extend down the back side of the ankle joint and thence forwardly beneath the ankle. These fingers and J-shaped arms are sewn to portions of the flat sock or sleeve blank so as ultimately to be disposed on opposite sides thereof. A padded tongue is tacked to one of two edges of the sleeve blank which are to be sewn together.
The flat sleeve blank with the attached tongue is then curved from its flat blank configuration into its sock or sleeve form, and seamed to itself to hold that shape. The seamed sleeve and its surrounding shell blank are then mounted on a male mold and heat and pressure applied in the molding step.
The shell blank is transformed by the molding from its soft foam state into a resilient semi-rigid skeletal state. In this form and configuration it possesses resilience, flexibility, and semi-rigidity. The formed shell is provided with lace apertures, eyelets or hooks for speed lacing, in approximately the same positions as these would be found in a high topped shoe. Lacing through these apertures, or the like, provides adjustability in the collar from which the stiffening fingers depend.
A pair of straps are affixed to the rear of the shell collar for forming a figure 8 support over the combined outer surfaces of the shell and sock. The strap ends are fastened behind the collar of the shell by hook and loop fasteners. The straps pass over and beneath the sock and provide an adjustability of tension which is not found in stirrup type braces. The straps preferably engage the outer surfaces of the stiffeners to provide an added element of support.